Tuesday , June 28 2022

"Donatiello I," the galaxy discovered by an amateur astronomer


An international team of astronomers confirmed the discovery a spherical dwarf galaxy at the far end of the Andromeda galaxy, according to the Canary Islands Astrophysics Institute (IAC).

The finding was made primarily by the amateur astrophotographer Giuseppe Donatiello, who found it while analyzing the various Andromeda images he captured between 2010 and 2013 in the Pollino National Park, in southern Italy. The new galaxy is called "Donatiello I" in honor of.

Observations made with the Great Telescope Channel (GTC) and Galileo National Telescope (TNG) have shown that this star set is 9.78 million light years.

Based on the position and distance between "Donatiello I," the researchers take on the hypothesis that it is a dwarf satellite of the elliptical galaxy, called "Mirach's ghost", due to its proximity to Star Mirach (the second brightest of the constellation Andromeda ).

The old stars

According to the data analyzed so far, the recently-hosted dwarf galaxy is composed mainly of old stars and its content resembles that of other galaxies relatively close to the Milky Way, such as the Draco Galaxy or Ursa Minor.

In the article that reports the discovery and characteristics of "Donatiello I", the IAC researcher Mike Beasley notes that "the absence of young stars and the lack of gas are typical of dwarf spheroidal galaxies, which ceased to form stars a few billion years ago."

On the other hand, David Martínez Delgado, A Researcher at the University of Heidelberg (Germany) and lead author of the article mentioned above, states that "it is very interesting that the theory of galaxy formation to achieve a complete inventory of dwarf galaxies in the vicinity of the local group. "

The so-called local group consists of about 30 small galaxies plus three large spiral galaxies: Andromeda, the Triangle Galaxy and the Milky Way, in which our solar system is located.

Martínez Delgado comments on the discovery of "Donatiello I", pointing out that "the ultra-deep images of large skyscrapers taken with small telescopes by amateur astro photographers can help completes the census of these galaxies with low surface brightness"which specifies that" currently can not be detected with maps based on the number of individual stars or in the detection of neutral gaseous hydrogen. "

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